(a) Draw a ray diagram of the Astronomical Telescope for the final image formed at infinity.

Answer

Ray diagram of astronomical telescope when image is formed at infinity.

ASTRONOMICAL TELESCOPE - IMAGE AT INFINITY.jpg

(b) A small telescope has an objective lens of focal length 140 cm and an eyepiece of focal length 5.0 cm. Find the magnifying power of the telescope for viewing distant objects when  

(i) the telescope is in normal adjustment, 

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(ii) the final image is formed at the least distance of distinct vision. 

Answer

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Transcript

Question 8 (Choice 2) A small telescope has an objective lens of focal length 140 cm and an eyepiece of focal length 5.0 cm. Find the magnifying power of the telescope for viewing distant objects when the telescope is in normal adjustment, In normal adjustment : Magnifying power m = 𝑓_0/𝑓_𝑒 = (140/5) = 28 Question 8 (Choice 2) A small telescope has an objective lens of focal length 140 cm and an eyepiece of focal length 5.0 cm. Find the magnifying power of the telescope for viewing distant objects when (ii) the final image is formed at the least distance of distinct vision. When the final image is formed at the least distance of distinct vision (25 cm) m = 𝑓_0/𝑓_𝑒 (1+𝑓_𝑒/𝐷) = (28×1.2) = 33.6

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Davneet Singh

Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 14 years. He provides courses for Maths, Science and Computer Science at Teachoo